/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/OnlinePurchaseInterface.h
Initiate the checkout process for purchasing offers via payment
void Checkout ( const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & UserId, const [FPurchaseCheckoutRequest](API\Plugins\OnlineSubsystem\Interfaces\FPurchaseCheckoutRequest) & CheckoutRequest, const [FOnPurchaseCheckoutComplete](API\Plugins\OnlineSubsystem\Interfaces\FOnPurchaseCheckoutComplete) & Delegate )